Garmin Activity Heart-Rate Zones

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds the key behavioral trait 'when available', clarifying that data may not always be present. This is valuable context beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence that contains all necessary information without redundancy. It is perfectly front-loaded and efficient.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simple nature of the tool and the presence of an output schema, the description is mostly complete. It lacks explicit mention of error conditions or behavior when the ID is not found, but the condition 'when available' partially covers this.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 67% schema description coverage, the description does not add further parameter meaning. The parameters are adequately described in the schema, and the description offers no extra guidance on their usage or format.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool retrieves heart-rate zone time data for a specific activity, with a condition of availability. The verb 'Get' and resource 'activity heart-rate zone time' are precise, and the function is easily distinguishable from sibling tools like garmin_get_activity or garmin_get_activity_details.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not explicitly guide when to use this tool versus alternatives. The phrase 'when available' hints at conditional usage, but no exclusions or alternative tools are mentioned. This leaves the agent to infer usage context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.